Automatic motor-control apparatus.



No. 872,515. v PATENTED DEC. 3, 1907. G. H. HILL. AUTOMATIC MOTOR CONTROL APPARATUS.

APPLICATION TILED IA! 2 1, 1908.

fiwentan Gearge hf fi/ZL W/Znesses Amy UNITED STATES Parana oFFroE.

GEORGE H. HILL, OF SOHENECTADY, NEW YORK, ASSIGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK,

nu'rom'nc Moron-Connor. APPARATUS.

Specification of Letters Patent.

Patented Dec. 8, 1907.

- Application ind Kay 21. 1906. Serial K008174388.

To all whom it may concern:

Be it known that I, GEORGE H. HILL, a citizen of the United States, residing at Schenectacy, county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Automatic Motor- Control Apparatus, of which the following is a s ecincation.

In atent No. 798,342, granted on Aug. 29, 1905, on anapplication filed by me, I have disclosed asystem of control comprising an automatic motor controller, together with a combined time-interval and throttle relay for controlling the operation of the automatic controller in such a manner that the current in the main circuit is maintained within safe limits. This relay comprises a shunt coil and a coil in series with themain circuit, and the system is arranged so that after each individual contact opens the relay is o erate'd through the action of the shunt 001 and is maintained in such 0 erated position so as to prevent the closing 0? additional contactors until the current in'the main circuit drops below a predetermined value. the parts of the relay have once been adjusted, the relay stops the automatic progression of the contactors whenever the main current rises above a predetermined value and does not permit acceleration under greater currents. In electric railways, where such control systems are frequently used, the cars at times run on level stretches and at other times u or down inclines, and, in case a car is disa led, it must be moved out of the way by another car. Therefore, in practice, the setting of the relay is usually made such that the motors may be started under current having a value just below that which would cause the wheels to slip, whereby a disabled. car may be pushed up hill by another car if necessary. The relay is then adjusted as to its time-interval feature so that when the car is on a level stretch of track a fairly smooth acceleration is obtainable by reason of the time interval function of the-relay alone; this being made possible by reason of the fact that on light oads the motors start and accelerate rapi ly,

- so that a counter-electromotive force is 'quickly established and thereafter quickly It is evident that, after make starting slow,as, for exam le, when a car is being accelerated on an inc ine under ordinary conditions,the relay permits the controller to out out resistance more rapidly than the co' erclectromotive force oi the motors inc-Tea s. This is because the pro gression of the, resistance-controlling conquentlysubjected to unnecessarily severe treatment, and the car accelerated in a jerky and disa eeable manner.

The 0 ject of the present invention is to provide means whereby the governing device for controlling the automatic operation of the controller is made flexible, so as to antomatically adjust itself to meet the requirements of different conditions of load.

The invention in its various as eots will be fully. set forth and its objects an' advantages will more clearly appear from the following detailed description taken in connection I with the accompanying drawing, wherein:

Figure 1 indicates diagrammatically a control system comprising a motor controller of the separately-actuated contact type rovided with a governing device arrange in accordance with the present invention; Fig. 2 is a diagram showing a somewhat modified form of overnin device; and Figs. 3 and 4 are detai s of the ash-pots on the relays.

The invention will be described as operating in conjunction with a'well-known form of controller used for service in electric railways, but it is of course not limited in its application to this particular situation or type of' ap aratus.

Re erence being had to the drawings; M Y

and Mrepresent the motors of a two-motor car equlpment C indicates a motor controller I of the separately-actuated contact ty e, in-

.therelay Q, is identical with the corresponding apparatus shown in my Patent No. 815,826, of March 20,1906 anda detailed description of the controller, except to such extent as may be necessary tomake clear the Operation of the present invention, is therefore unnecessary. j

K and K are master' controllers connected in parallel to the train wires ll from "which connections are made to the actuating .icOllS of the controller.

W is the improved overning device for the grou ofautomatica ly and progressively actuate contactors. This device consists of a relay w, correspondin to the relay 0 of Patent No. 815,826, and t e relay E of Patsomewhat, similar relay w.

ent N o. 7 98,342, together with a second On the relay w is a coil 1 arranged in the actuating circuit of the grou ofautomatically pro ressing contacts an a coil 2 arranged in th cuit. On the other relay are coils 3 and 4 corresponding, respectively, to and arran ed in series with the coils 1 and 2 on there ay w. The relay w is provided with. a dash-pot 5 so proportioned that it requires but a short timewhich, in an equipment of the character illustrated, may be about onequarter of a second,for the core of the relalyl'lto dro The relay to has a dash-potjfi w 'ch ma es the core of this relay drop much slower than that of thelother, namely, "1n the case assumed, in' about three seconds.

The dash-pots 5 and 6 have outwardly openmg check valves as indicatedin Fig. 3. The re ay w is so proportionedthat when the coilis deenergized and the current value in the coil 2 is not above the value best adapted for acceleration under the heavier normal loads, which, in the case assumed, will be about 120 amperes,+the core of-the relay isfree to drop and close the relay contacts.

The relay w, on the other-hand, is 'so designed that after it has 0 erated, the core belgins tov drop as soon as t e motor current fa 5 below a much higher value than that at l which the other relay 1s free to close, namely,

- the value at which it is desired to accelerate under abnormal loads. When the setting of relay w is 120 amperes. that of 11) will be about 160 amperes. The 'operationof this controlling device or governor will be more fully understood in' connection. with a descri tion of the operation of the motor control er. V

Assuming that the main switch X and the switch X' adjacent the master controller K are closed, and that the controller is moved so as to bring its movable contacts into en-, gagement with the row, of fixed contacts.

along line a--a, current passes from current collector T, through the switches X, X

' blow-out coil BO, controller contact k,

through the movable contacts of the controller, contact is, through train-wired, through the actuating coils of the line switches, to ground. 'A branch circuit extends from controller contact 1c, to contact thence through the movablecontalcts of e motor cir-' -ciate man a the controller, to contact k to train wire Z,

through the interlock p associated with parallel contactor P through'the actuating coil of the series contactor-S, through the interlock t associated with the lin'e contactor T, through the interlock b associated with an S are closed and the motors are connected withthe source of supply in "series with each other and with the resistance sections R? to R When the mastercontroller is moved to its second position, namely, that in which the movable contacts engage with the fixed contacts along line b-b, the control circuits previously traced remain, and an additional branch asses from controller contact 7: through t e movable contacts of the controller, contact k, and thence totrain wire 1., through contacts 7 and 8 of the relays w and w, respectively,-the contacts 7 and 8 being in parallel with each other,thence through the coils 1 and 3 of the relays, through the u per contacts .of the. interlock s assowith the series switch, throu h the lower'contact of interlock r throu contact q of relay Q, through the actuatmg coil of switch R through the interlocks r, 1" and 1", to ground. Switch R is accordingly closed, cutting resistance section R out of the motor circuit, shunting its actuating cir- 'cuit from the lower (contacts of interlock r to the upper contac s of this interlock,so that an actuating urrent may thereafter 1"", throug the lower contactsof interlock r, and through the actuating coil of the resistance contactor R ,'and shifting the actu'ating circuit for the series contactor from the lower contact of interlock r to the upper contacts of this interlock so as to provide a bridging contactor B, thence through the I lower contacts of interlocks r r 1* and r,- to, ound. Thus, the switches T T ,'T T5 maintaining circuit for the contactor R. In

loads, aswhen a car is started on a level stretch. If, however, the motor current rises slightly above. the value necessary to maintain the rela w lifted, then the interval of time during w ich the contact 7 remains open is increased, and, provided that the cur- 5 rent diminishes sufiiciently before the slowmoving core of the relay w has completed its descent the controlling action of thegovernor is still due entirely to t e relay w, act1ng, however, in the dual capacity of a t me-interval and throttle device. This latteris the nor- 100 I flow throu h the upper contacts of interlock l i mal operation of the governor when a fairly a a value that, not only is the relay w held in its operated position, but the relay w is also prevented from closing. The time elapsing between the closing of one contactor and the next is now longer than before, namely, it is equal to the time interval settingof the relay 10 plus the time during which the motor remains above the minimum value which is sufficient to hold the core of the relay w up. In other words, as long as the motor current is maintained above the value of relay w (120 amps.) for the length of time between ste s that w is set for(3 secs.) the motors Wil be accelerated at the current rate of w relay (160 amps). Thus it will be seen that the governor adjusts itself automatically to Provide a smooth acceleration under varying oad conditions and at the same time permits the motors to take sufficient current tooperate most advantageously without in any case being liable to be sub ected to 'injuriously heavy currents. The remaining resistance contactors are closed in automatic succession, subject to the control of the governor W but, since the tracing of the various circuits whereb the resistance is all cut out of the motor circuit, the bridging connection formed, the motors again connected in parallel and then the resistance a ain removed, are not necessary to a clear understandin of the present invention, discussion thereo is omitted.

In Fig. 2 a modified form of governor is illustrated. The relay w is the same as the relay win Fig. 1. The relay 10, however, has but a single coil 9, this coil being arranged in the motor circuit. The contacts of this latter relay control a shunt'about thecoil 2 of the relay w, this shunt containing a resistance 11. The dash-pot 12 of the relay to is arranged so as to permit the core of the relay to dro freely but retards its upward movement or a rather long riod, say for four or five seconds. This das -pot has an inwardly opening check valve as shown in Fig; 4. Un-

der light loads the relay w alone controls the operation of the contactors, actin as a timeinterval device. When the load is that corresponding to the load on the motors when the car is goingu hill, more current is taken and the core of the relay is held u through the action of the coil 2, until a sad; .value is reached. Under abnormally heavv loads the core of relay w is held up until relay to has time to act. Thereupon the resistance 11 is placed. inshunt-with the coil 2 and the effect of the motor current upon the rela w diminished. Consequently at a pre etermined current value the core of the rela w will drop and the contactor-actuating circuit be completed. The governor in this instance prevents excessive currents from passing .through the motor under abnormalload conditions for the reason that the resistance 11 is so proportioned that when the current of the motor circuit risesto a dangerous value, sufficient current will still flow through the coil 2 to hold the relay w u thereby preventing further-reduction o the resistance in the motor circuit while the dangerous current lasts.

Although I have described my invention in detail as embodied in preferred forms, I do not desire to limit the invention to any particular form shown but in the appended claims aim to cover not only the particular forms shown but all the forms coming Within the scope of the claims.

What I claim as new and desire to secure by Letters Patent of the United States, is,-

1. In combination, an electric circuit including a translating device, a controller'for varying the conditions of said circuit, automatic actuating means for said controller, and an electrores onsive governor for automatically control mg the rate of operation of said actuating means to limit the current in said circuit to different predetermined values under different predetermined conditions of said translating device.

2. In combination, a motor, a speed. controller, automatic actuating means for said controller, and an electroresponsive governor for automatically controlling the rate of o eration of said actuatingjmeans to limit t 6 motor current to differing values corresponding to differing loads.

'3. In combination, a motor, a speed con-- troller, automatic actuating means for said controller, and an electrorespons ve overnor for controlling the operation of said actuating means, said. governor including a plurality of coils in the motor circuit and 006 erating elementsconnected and arrange to govern the rate of operation of said actuatmg means to limit the motor current to a redetermined value on a certain load and to imit the current to a different predetermined value on a different load.

4. In combination, a motor, acontroller' cuit, automatic actuating means for said con'- troller, and an electroresponsive governor cuit, actuating means for said-contacts arranged to actuate the contacts in autoniatic' Succession, an electroresponsive governor for said actuating means arran ed to control the'rate of progression of said contacts to limit the motor to a predetermined value on a certain load. and different load.

; 6. In combination, .a motor, a controller for varying the cpnditions of the motor cirfor said actuatin means arranged to cause the controller to e operated at a predeter-' mined rate at certain loads and to vary the rate of operation of the-controller so as to anceis eliminatedfrom the motor circuit at 1 a predetermined rate during certain loads and during certain other differing loads ata rate or rates limiting the motor currenttopredetermined differlng values.

8. In combination, an electric circuit including a tra'nslatingdevice, a controller for varying the conditions of said circuit, means for automatically actuating said controller step by step, anda plurallty of combined 'throttle and .time-interval relays having different settings for controlling the controller-actuating means.

9. In combination, an electric circuit, a controller for varying the conditions of said circuit, means for automaticall said controller step by ste an a plurality of relays operating in para lel to govern the operatlon of-said controller-actuatmg means, said relays each havin acoil arranged in said. circuit and the sett ngs of the relays be;

the controller.

ing'difierent.

10. In combination, anelectric circuit, a controller for varying theconditions of said circuit, means for automatirpalliy actuating saidcontroller step .by ste an .of combined time-interva and throttle .relays for governing the controller-actuatin means, saidrelays operating in parallel wit each other and having corresponding coils connected in series witheach other. 11. In combination, an electric circuit, a controller for-varyingthe conditions of said circuit, means for automaticall actuating said controller step by ste an a plurality of combined time-interva and throttle relays for governing the controller-actuating means, said relays having different settings and operating in parallel with each other.

to a different value on'a actuating a plurality '-12. In combination, a motor, a controller I vfor varying the conditions of the motor .cir-

cuit, means for automatically'actuating said controller step by step, and'a pluralit of combined time-interval and throttle re ays ,for varying the conditions of the motor circuit, electroresponsive means for automatic-- ally actuating said controller step by step,

'means, .and a plurality" ofcombine and a plurality of combined time-interval and throttle relays operating in parallel-to control the circuit of said electroresponsive means said relays having different settings.

14. In combination, a.:motor,'a contro ler for varying the conditions of the motor circuit, electroresponsive means for automatically actuating said controller step by step,

and --a plurality 'of combined time-interval and throttle relays'operating in parallel to control the circmt-of said electroresponsive means, said relays having corres ondin coils connected in series with each ot or an the setting of the relays being different. 15. In combination, a motor, a controller for varying the conditions of the motor cir'-.' cuit, electroresponsive means for automatic- .allyoperating said controller'st'ep by step,'a

control circuit for said electrores onsive timeinterval and throttle relays actuatin eration of the said electroresponsive means.

contacts" in said control circuit to check t e opa 16. In combination, a motor, a controllerj for varying'theconditions of the motor circuit, electroresponsive meansfor automatically operatingsaid controller step by step, a

control circuit for. said electroresponsive means, and a plurality of-combined timeinterval and throttle relays actuatin contacts in said control circuit to check t e 0p- 1 eration of the said electroresponsive means; said relays having. different settings and the arrangement being such that all of the'relays.

are actuated at each step of the operation of 17. In combination, a motor, a controller cuit, means for automatically actuating said controller step by step, a plurality ofrelays operating to control the operation of said controller actuating means, and 'means for operating said relays at eachste of the operation of the controller, ,said re ays having throttle coils arranged to maintain the differs ent relays in the operated positions under different values of motor current.

18. In combination, a motor, a con for varying the condition of the motor circuit, means for automatically actuating said controller step by step, aplurality of relays.

operating in parallel to control the o eration o troller said actuating-means and means or oper- 'for'varying the condition of the motor cir- 115 ating said relays at each step ofthe operation of the controller, said relays havmg'g throttle coils for maintaining the. different relays in the operated positions under different values of motor current, and checking I devices having differing settlngs associated with said relays 19. In combination, a motor, a controller for varying the condition of the motor circuit, means for. automatically actuating said controller step by step, a control circuit for said actuating means, a plurality of relays having contacts in said control circuit, means for operatin said relays to open said contacts at each step. of the operation of said controller, throttle coils on said rela s arranged to hold the different relays in t e opcrated positions under different values of motor current, and checking devices associated with certain of the relays and arra ed to retard the closing movement of the re ay having the highest current setting to a greater extent than the relay having the lowest current setting.

20. In combination, a motor, a controller for varying the condition of the motor circuit, clectroresponsive means for automaticall y actuating said controller step by step, a control circuit for said electroresponsive means, a plurality of relays having contacts arranged in parallel in said control circuit,-

incurs for operatin the said relays to open said contacts at each step of the operation of I arranged to hold the relays in the operated positions under different values of current 1n the motor circuit, and dash-pots on said relays for retarding the movement of the relays to the circuit closing osition, the dashpot on the relay having the highest current setting bein arranged to retard its relay more than the dash-pot which is connected to the relay having the lowest current setting.

21, In combination, a motor, a motorcontroller comprising a plurality of individual switchesarranged to operate in automatic succession, an actuating circuit for said switches, a pair of relays havin contacts arranged in parallel with each ot er in said actuating circuit and having lifting coils connected in said actuating circuit, means associated with each of said switches for shifting the actuating circuit to a following switch, throttle coils on said relays arranged to hold said relays in the lifted positions un der different values of motor current, and a dash-pot on the relay having the hi her current setting arranged to cause its de ay.

In witness whereof, I have hereunto set 60 my hand this 19th day of May, 1906.

GEORGE H. HILL.

Witnesses:

BENJAMIN B. HULL, HELEN ORFORD. 

